This invention relates to a heating cooking appliance which includes a casing defining a heating chamber in which food is cooked by means of high frequency waves, high-temperature gas or radiant heat, and more particularly to such a heating cooking appliance wherein a turntable on which the food to be cooked is placed is rotatable with vertical movement.
Japanese Published Utility Model Application No. 52-12993 and Japanese Laid-open Patent Application No. 52-3743, for example, each disclose a high frequency heating apparatus comprising a casing defining a heating chamber in which food is cooked and a magnetron generating high frequency waves or microwaves delivered into the heating chamber and a turntable on which the food to be cooked is placed and which is disposed in the heating chamber so as to be rotated by drive means with a vertical movement. Since the turntable and therefore, the food placed thereon is moved in the directions of three dimensions in the heating chamber in such a high frequency heating apparatus, the food can be uniformly exposed to the microwaves and accordingly, a uniform heating effect may be expected over the food. More specifically, it is expected that an unevenness in the heating against the food in the horizontal direction can be overcome by the rotation of the turntable and further that the unevenness in the heating in the direction of the thickness of the food can be overcome by the vertical movement of the turntable. In a turntable drive mechanism employed in the conventional high frequency heating apparatus, upon rotation of the turntable, a plurality of rollers mounted on shafts secured to the turntable are moved along an undulate surface formed on a track member secured in the heating chamber. However, in the above-described construction, the turntable is rotated with the vertical movement such that a portion of the food placed on the turntable always passes certain, fixed upper and lower limit spatial points. Consequently, the portion of the food placed on the turntable is continuously exposed to the high or low density of microwaves, which prevents the dissolution of the unevenness in the heating in the direction of the thickness of the food.